Receptacle for a plurality of bipolar connections



April 13, 1 4 c. R. HARTRANFT 2,675,527

RECEPTACLE FOR A PLURALITY OF BIPOLAR CONNECTIONS Filed Oct. 24, 1950 Fig! Inventor 1 B 2mm.

WW 8m Patented Apr. 13, 1954 RECEPTACLE FOR A PLURALITY |OF BIPOLAR CONNECTIONS Clifford R. Hartranft, Philadelphia, Pa.; Bertha Marie Hartranft, administratrix of said Clifford R. Hartranft, deceased Application October 24, 1950, Serial No. 191,875

1 Claim. 1

This invention relates to electric connectors and more particularly to receptacles forming the sockets for a plurality of outlets, and it has for its main object to provide a receptacle of the above stated type which provides simultaneously outlets for three prong non-interchangeable plugs such as used for business machines and the like and outlets for the standard conventional two prong plug, said receptacle being at the same time simple and efficient and of a sturdy construction and adapted for use in connection with two conductor networks without requiring a third conductor.

The receptacle according to the invention essentially consists of three metallic members and of an insulating body, the said three members being insulated from each other by the said body, and one of said three members being a base plate forming the bottom member of the receptacle which rests on and is attached to the Wall or other structure carrying the receptacle. Said base plate member carries a ground contact and the two other metallic members are arranged on both sides of said base plate, each of said laterally arranged members consisting of a side plate with lateral contact prongs carrying wing members projecting inwardly towards the longitudinal axis of the base plate, the wing members on one side being inclined at a pre-selected angle towards said longitudinal axis and the prongs forming the contact sockets on said members being arranged near the ground contact on the base plate. The wing members on the other side of the base plate also form an inwardly projecting strip at right angles to the longitudinal axis and to the side plate and the contact prongs of the two members on both sides of the base plate form the socket members for a standard outlet ada ted to be used in connection with the conventional plug.

The ground contact arranged on the base plate together with the two adjacent contacts of the two side members form a standard polarized outlet of the non-interchangeable type while the other contacts, as aforestated, form a conventional standard outlet. Two types of connections can thus be made on the same receptacle.

Each of the bus connectors or cables of the network with which the receptacles are associated may be connected with one of the two side plates, no third conductor being necessary in this case for the ground contact on account of the direct grounding of the base plate which furnishes the ground potential for the ground contact of the polarized. outlet. 7

The receptacle, notwithstanding its simple construction, is therefore adapted for a connection with two types of plugs, one being of the noninterchangeable type and the other being of the conventional two prong type.

The specific objects of the invention will be apparent from the following detailed specification.

The invention is illustrated in the accompanying drawings showing one modification thereof. It will however be understood that the modification illustrated in the drawing is shown by way of example only in order to explain the principle of the invention and the best mode of applying said principle. The specification and the drawings do not provide a survey of the various modifications by means of which the invention may be carried into efiect and a departure or modification of the example which has been illustrated is therefore not necessarily a departure from the principle of the invention.

In the drawings:

Figure 1 is an elevational front view of the receptacle according to the invention when covered with a cover plate and mounted in the wall.

Figure 2 is a plan view of the receptacle.

Figure 3 is an elevational side view of the receptacle, parts of the insulating body being shown as broken away.

Figure 4 is a sectional plan view of the receptacle according to the invention, the section being taken along line l-4 of Figure 3.

Figure 5 is a perspective View of the metallic parts of the receptacle, the insulating body being removed while the metallic parts are shown in the position in which they are held.

The connector according to the invention comprises essentially the three metallic members l0, I8, 38, embedded in an insulating body 50.

Of the metallic members the central member is a base plate or bridge support H! which is provided with upstanding end portions l l and I2 which carry flanges I 3 and l 4, each provided with a hole or holes for mounting the receptacle at the desired place by means of screws. A hole I5 is provided in the base plate for a purpose which will be explained below.

On both sides of the base plate or bridge member Ill contact carrying assemblies I8, 38 are arranged. Each contact carrying assembly includes a side plate 23 provided with ears 2|, 22 each having a threaded opening or eye 2-4, 25

respectively, into which threaded binding posts p e y, may be inserted.

3|, 32 which form one of the socket contacts 23.

The second wing member is arranged at right angles with respect to the side plate 23 and is of U-shape carrying three contact prongs 33, 3 35 projecting upwardly from the middle of the legs of the U-shaped strip and from the bridge piece joining the legs respectively. The two contacts 34 and 35 in this case may consist of bent strips which have base portions running towards each other until the proper distance for the upstanding parallel prongs is reached.

The contact assembly 38 is similarly provided with a sid plate 43 carrying contacts 658 and 58, the former being a two pronged contact while the latter is a three pronged contact, the construction being identical with the construction of the contact carrying assembly 8.

The base plate or bridge support l6 itself carries a further contact 52, projecting from the base plate on that side on which the two pronged contacts are arranged at a proper distance from said contacts. The prongs of the contact 52 are substantially parallel to th median plane of symmetry of the base plate it) while it will be noted that the two pronged contacts 28 311G138 have their parallel prongs arranged at an angle towards the longitudinal axis of the base plate, this angle corresponding to the angle at which the wing members it are arranged. The purpose of this arrangement will be explained below.

The two three pronged contacts and 53 are aligned along a transverse axis which is at right angles to the longitudinal axis of the base plate ill. Of the three prongs two, 34 and in assembly 18, ar parallel to each other and to the transverse aXis and the third prong, 33 in assembly i8, is arranged at right angles thereto.

The contact 52 mounted on the base plate ill may be held by a screw or rivet on base plate l9 or by an arm 55 which ends in an eye or sleeve 55 encircling a hollow cylindrical sleeve 55 arranged U in the center of the base plate 19 around the axis passing through the hole i5. Through the hollow interior of the sleeve 55 a screw bolt may pass which holds the parts of th receptacle together and which also holds the cover plate and fixes the receptacle on the structure on which it is mounted.

The insulating body 68 of the receptacle comprises a top portion which is provided with the two outlet caps 62, 53, one of the said outlet caps 53 being provided with three openings 65, b5, 56 arranged at such an angle that no ordinary plug connection can be inserted and a three prong plug connection can only be inserted in one way which is well defined. The second outlet cap 62 is provided with two T-shaped slots in a well known manner with the two slots iii, 53 placed apart at such a distance that an ordinary plug with two prongs may be inserted into this receptacle outlet.

The insulating body to is provided with two main cavities H, 72 for taking up the contact prongs projecting from the metallic parts and it is also provided with slots 13, M which accommodate the side plates 23, 43 of the contact carrying assemblies 1-8 and 38. The shape of the insulating body is best seen in Figures 3 and 4. The bottom portion of the insulating body is seated on the base plate H] which holds it in the center. A central hole Bl may be provided in the insulating body 68 for accommodating the sleeve 55 and the central screw which holds all the parts of the receptacle together and also holds them on the structure on which they are fixed.

The cover plate ill, Figure 1, may be placed over the two outlet caps which project from it in a well known manner concealing the base plate completely and a screw bolt 15 holding the base plate and the insulating body may also hold the cover plate 10 and may .pass through the hole I 5 of the bas plate 10 in order to hold the receptacle on the structure on which it is mounted. The slotted head of the screw bolt I5 may be accessible from the outside to allow removal of the receptacle and of the cover plate 10 insa single operation.

The bus bars or cables of an A. C. or D. C. network (not shown) are preferably connected with or attached to the binding posts 26, 21,86, 81 respectively. It is assumed that the bus bars form part of a distribution system. Th neutral or negative bus bar is therefore always attached to the binding posts 26, 2'! while the positive or high voltage bus bar is always attached to binding posts 86 or Bl. Obviously if this connection has been made correctly, the receptacle is polarized and contacts 28 are always negative while-contacts 38 are positive. Likewise contact 30 is always negative while contact 50 is always positive. The contacts may be marked accordingly.

The base plate III which forms the bottom of H the. entire structure is grounded either through the wall or through a special means. This ground potential is also transmitted to the contacts 552 as the plate is in contact with the arm '5 and the sleeve 56.

The receptacle is thus polarized throughout and carries an outlet for a non-interchangeable three pronged plug such as used for-businessmachines or the like and a further outlet which is of standard construction and which may be used for any standard type of plug. Usually and in the known constructions both types of outlets are necessary and two separate receptacles are used for every business machine. Only one type of receptacle is however necessary with the receptacle according to the present invention. The supporting or base plate I0 when mounted automatically becomes grounded and therefor provides a ground potential which is necessary for the polarized or ground terminal, no special wire connection being necessary for such a purpose. The receptacle provides a combined outlet in which certain outlet sockets have a definite potential. Thus in a D. C. systemthe receptacle is definitely polarized when the cables or bus bars are joined to its terminals. When used in an A. C. system it will be clear that the receptacle may be used for distinguishing between the newtral conductors and phase carrying conductors. Finally the receptacle may be used like an ordinary multiple outlet for A. C.

It will be clear that while on the one hand many standardized constructions have been used the construction may be changed in many ways with changing standards or for other reasons without in any way departing from the essence of the invention as defined in the annexed claim.

Having described the invention, what is claimed as new is: V

A receptacle with a "grounded metallic base plate mounted on an insulating housing'lraving a cover plate with two outlets arranged at a distance, one of them giving access to a normal two contact socket and the other to a three contact socket, said insulating housing consisting of an outer elongated body provided with lateral openings and an inner central block having a central bore and being provided with substantially parallel faces integral with, but partly separated from the elongated body by longitudinal slots, the inner central block being of reduced height and separated from the end portions of the other elongated bodies by cavities, a portion of one of said cavities being formed by a recess in the inner central block, comprising three metallic contact carrying members mounted on said insulating body in positions in which they are insulated from each other, two of said members being contact strips held in the aforesaid longitudinal slots and carrying contact prongs at each of their ends, said strips being bent at one end, so that the prong carrying portions are at an angle to the main portions of the strip, the contact prongs at opposite ends of one strip forming part of two diiferent sockets, while the contact prongs at the two bent end portions at the opposite ends of different strips form contacts of the same socket, the third member including a central sleeve member in operative connection with the grounded metallic base plate, arranged within the central bore of the inner central block and substantially at right angles to the strips and to said grounded metallic base plate, said sleeve member being provided with a prong carrying metallic strip, projecting from the center towards one socket formed by a contact group which consists of the prongs projecting from the bent end portions of the metallic contact strips, and the prongs carried by the last named strip and connected with ground, and terminal binding posts on each of said contact strips to connect the same with an electric supply line having a definite characteristic, the receptacle being thus adapted for connection with plugs of business machines having one contact prong adapted for ground connection and with normal plugs.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,786,292 De Reamer Dec. 23, 1930 2,051,856 Hubbell Aug. 25, 1936 2,323,736 Tousley July 6, 1943 

